[ He's not so much trying to make Ianto feel better by saying what's comforting as he's trying to share his own experience and maybe through that minimize the hurt. It's something he's good at, most of the time, telling the truth all naked and cold because no one else will. Someone should and so he will and sometimes he's not even an ass about it.
There's another non-committal noise of acceptance followed by silence and music. Maybe he'll light another cigarette in a while or strike up a conversation about nothing in particular and eventually, when he can't justify hanging around anymore, he'll head home. It's just a couple of floors between them, he'll be in the building.